Performance Study of Anti-galling Self-lubricating Coating for Premium Thread Connection for Tubing and Casing

The base material is made of API grade P110 steel，while the surface is sprayed with self-lubricating coating which consists of polyamide-imide-epoxy resin（PAI-EP）as a binder and molybdenum disulfide（MoS₂） and polytetra fluoroethylene（PTFE） as solid lubricants.The influence of the content of MoS₂and PTFE on the adhesive force and friction characteristics of the coating is studied by means of coating adhesive force tester and friction wear tester.The test results indicate that the self-lubricating coating shows good adhesive force and friction-wear characteristics when the content of modified MoS₂in PAI-EP is 30% （mass fraction） and the content of PTFE in PAIEP is 7% （mass fraction），with curing temperature of 280～300 ℃ and holding time of 10～15 min.The self-lubricating coating prepared under the above-mentioned condition can meet the requirements of anti-galling of premium thread connec-tions for tubing and casing.